fix(credit): honour USE_SAFE_PRICES_FLAG in partial-liquidation collateral check

[SashaMIT]

Problem

partiallyLiquidateCreditAccount does the two things that, everywhere else in this facade, switch the final collateral check onto safe prices:

1. _tryWithdrawPhantomToken routes an adapter call into an arbitrary registered target contract via _externalCall (L421).
2. Two collateral withdrawals (L427-428).

It captures the returned flags — but reads them only for EXTERNAL_CONTRACT_WAS_CALLED_FLAG (L424) and then passes a hardcoded useSafePrices: false into _fullCollateralCheck (L434). L434 is the only hardcoded false in the facade; the multicall path reacts to the identical condition with useSafePrices: flags & USE_SAFE_PRICES_FLAG != 0 (L648).

Safe pricing is materially stricter, not cosmetically: PriceOracleV3._getSafePrice returns min(main, reserve), and returns zero for any token with no reserve feed configured. So a check that should have failed on safe prices can pass on a manipulated main-feed price.

The git history supports this being an omission, not a decision: the useSafePrices: false literal entered this function in e3ff71e (feat: partial liquidations), while the phantom-token adapter call was grafted into the same function later, in 4c7d434 (feat: phantom token withdrawals). The safe-price decision predates the introduction of the external call it was meant to guard against.

Fix

Pass flags & USE_SAFE_PRICES_FLAG != 0 instead of false, matching the multicall path's handling of the identical condition.

Verification

forge build is clean (all lint warnings pre-exist in contracts/test/). One-line change inside the existing flags plumbing; no interface or signature changes.

Made with Cursor

Made with Cursor

[SashaMIT]

Superseded by a stronger fix: always use safe prices after partial-liquidation withdrawals (matches multicall withdraw semantics; #313 only forwarded the phantom adapter flag). Closing in favor of the new PR.